Yes, I believe Jody Daily and Kevin Kidney did design the look of the parade. (Same as Soundsational).
It definitely reflects their love of nostalgia, early 20th century Disney toys, and their signature 2-d flat, illustrative whimsical aesthetic.
Steven Davison's facebook page has a little info on who worked on it.
As for re-using parade elements from before, why not? If it works, it works.
And as for Marie, I don't know if they're exactly trying to 'make her hello kitty'. They have a great cat character (3 here to be exact)...why not use them? Yes, the Japanese love the character, but I believe that also reflects certain Asian cultural attractions/meanings to cats.
Plus, in this parade, she's actually represented alongside her two brothers. Having all three the Aristocats is great (and nice to see they developed full costumes for them all...perhaps they'll get to show up in other parks and parades).
As for the parade, I just think Steven, and certainly Jody and Kevin, made an effort to bring out some rarer characters/films. And it's great!!!